Neural prostheses to restore hearing to the deaf, sight to the blind, and motion to the paralyzed are at the leading edge of the emerging field of neuro-engineering. However, laboratory evaluation of these devices prior to human use is necessary in order to ensure their safety and efficacy. An implantable, 32-channel neural recording system will be developed to facilitate the evaluation of cochlear implants and other neural prostheses in animal studies. The proposed system will be specifically designed to recover quickly from the large electrical artifacts produced by neural stimulation. It will transmit 32 channels of continuous neural data wirelessly across the skin, allowing studies to be done in awake animals. Because power and data will be communicated wirelessly, there will be no need for connections to the device through the skin (percutaneously). This will avoid some of the problems associated with percutaneous connections such as increased infection rate, damage to connectors, noise pickup on exposed leads and, for developing animals, possible damage to their fragile skulls. The proposed system will be used to compare auditory midbrain responses to monopolar and bipolar intracochlear stimulation. Channel interaction will be compared for these two stimulus modes using a simultaneous masking procedure in anesthetized and awake animals. Because channel interaction can limit spectral resolution for cochlear implant users, the results of these studies could have significant implications for cochlear implant design. Relevance: Neural prostheses to restore hearing to the deaf, sight to the blind, and motion to the paralyzed are at the leading edge of the emerging field of neuro-engineering. However, laboratory evaluation of these devices prior to human use is necessary in order to ensure their safety and efficacy. A neural recording system will be developed to facilitate the evaluation of cochlear implants and other neural prostheses in animal studies.